This invention relates to the field of rubber footwear typically molded of natural or synthetic rubber with a significant degree of resilience. By the term "rubber footwear" throughout this disclosure, it is intended to include overshoes, rubbers, boots and the like which are typically of a relatively thin wall construction held on the shoe or boot by the elasticity of being stretched over the regular footwear. This type of footwear such as those manufactured under the trademark "TOTES" has the advantage of being light in weight and capable of being easily stored and carried in small pouches for ready unexpected use. This elasticized footwear also has the advantage that it stays firmly on the shoe despite the conditions. On the other hand, this type of boot must be very carefully constructed of fine materials or the service life is extremely short. The rubber material must be truly elastic or else the stretching over the boot will cause a rip or tear after only a short period of use. The rubber used in these footwear provides only moderate slip resistance particularly on ice.
Various types of abrasion materials have been used to aid in walking on ice. These include special cleats that may be strapped to the feet. It is certainly well known that cleats in rubber tires provide the utmost in ice driving safety. However, the use of abrasive materials such as stone or steel cleats wear out, become rounded and loose their effectiveness very quickly if used on road and sidewalk surfaces. The abrasive characteristics of a concrete sidewalk or stone filled asphalt are high. Other abrasive surfaces ground against the concrete or asphalt quickly wear out by rounding the sharp edges or dislodging the abrasive particulate secured to the surface.
In U.S. Pat. No. 1,634,540 to H. C. Harrison he describes rubber footwear that may be turned inside out and worn with either side showing varying colors. A. G. Timson, in U.S. Pat. No. 2,409,813 describes a reversible shoe again to covert the shoe to a combination of colors. In U.S. Pat. No. 2,901,840, M. P. Ferguson describes a convertible snow boot and over boot with a stiffening insole into which a platform sole section can be added.
None of the above articles nor any of the prior boots described above attain the following objects and other objects that will be clear from a complete reading of the disclosure.
It is an object of this invention to provide convertible rubber footwear which may be easily stored but yet will provide slip resistance not only on wet surfaces but also on icy surfaces.
It is an additional object of this invention to provide safe rubber footwear with means to protect the ice gripping surface.
It is a further object of this invention to provide a surface with high resistance to slipping on ice with means of protecting that surface when the footwear is used on equally abrasive surfaces.
An additional object of this invention is to provide rubber footwear which may be used on both ice and wet surfaces with increased durability on both anti-slip characteristics.
It is a further object of this invention to provide rubber footwear that protects the shoe on which the footwear is worn from both the elements and from excessive wear.
The above objects have been attained and the deficiencies of the prior art have been satisfied by my invention hereinafter described.